Regional variation in HIV clinical trials participation in the United States

To ensure generalizability of clinical research results, it is important to enroll a heterogeneous population that is representative of the target clinical population. Earlier studies have found regional variation in participation in human immunodeficiency virus (HIV) clinical trials, with the lowest rates seen in the southern United States. Rates of new HIV diagnoses are highest in the South, highlighting the need for in-depth understanding of disparities in clinical trial participation. We evaluated whether regional variation in study participation remains, and describe factors that facilitate or prevent HIV clinical trial participation by region.

A one-time, anonymous, bilingual, self-administered survey was conducted among HIV-infected adults receiving HIV care at all 47 domestic AIDS Clinical Trials Group clinical research sites, with a goal of completing 50 surveys per site. χ(2) tests were used to evaluate differences in knowledge of and participation in HIV clinical trials by region, including Northeast, Midwest, South, and West regions. Multivariable logistic regression was used to estimate odds ratios and 95% confidence intervals (CIs) for the effect of region on knowledge of and participation in HIV clinical trials.

Of 2263 completed surveys, 2125 were included in this analysis. The proportion of respondents in the South who reported knowledge of studies (66%) was significantly lower than in the Northeast (76%), Midwest (77%), and West (73%) (P = 0.001). Respondents in the South also were the least likely group to report ever having tried to or having participated in a research study (51%) compared with respondents in the Northeast (60%), Midwest (57%), and West (69%; P < 0.001). After adjusting for age, sex, education, race/ethnicity, tobacco use, and alcohol use, the odds ratio for knowledge of and participation in clinical trials for the Northeast (1.36; 95% CI 1.07-1.72) and West (1.85; 95% CI 1.39-2.45) remained significant compared with the South. African American respondents in the South were the most likely population group to report not understanding research studies (15%) as a reason for not participating, compared with the Northeast (9%), Midwest (8%), and West (6%; P < 0.001).

Significant regional variations in knowledge of and participation in HIV clinical trials exist. Our results suggest that increasing awareness and understanding of research studies, particularly among African Americans in the South, may facilitate HIV clinical trial participation that is more representative of the HIV-infected population across the United States.